Three-winding switch coupling inductor voltage-multiplying DC boost converter

Abstract

The invention discloses a three-winding switch coupling inductor voltage-multiplying direct-current boost converter, and relates to the field of power electronic converters. The invention aims to solve the problem of conduction loss of a traditional DC boost converter in high-voltage gain application. The direct-current voltage source is directly connected with the inductor L1 and can continuously provide relatively stable energy for the circuit, so that waveform changes such as voltage of an output capacitor and voltage of a direct-current link are relatively stable. The power switch is used for realizing on-state and off-state working modes, voltage distribution is optimized, the working mode enables elements to bear appropriate voltage at different stages, and certain elements are prevented from bearing too high voltage, so that the voltage stress of the elements is reduced, and the energy conversion efficiency and the boosting capacity are further improved. The conduction duty ratio range of the power switch is adjustable, the diversity of control strategies is increased, and different application scenes can be adapted by changing different conduction duty ratios.

Description

Technical Field

[0001] The invention belongs to the field of power electronic converters. Background Art

[0002] Boost converters are widely used in the front-stage converters of distributed power systems to achieve the boost function. Traditional DC boost converters, such as Boost converters, face great challenges in the pursuit of high voltage gain. As the voltage gain requirements increase, the duty cycle of the switch tube needs to be greatly increased. In high voltage gain applications, the switch tube and diode are subjected to large voltage stress and current stress. This requires the selection of power components with high withstand voltage and large current capacity, which not only increases the cost, but also high withstand voltage devices usually have a large on-resistance, which will lead to higher conduction losses. Therefore, its boost capability is very limited and is not suitable for high voltage gain DC power conversion occasions. Summary of the invention

[0003] The present invention aims to solve the problem that in a traditional DC boost converter, in high voltage gain applications, the switch tube and the diode are subjected to large voltage stress and current stress, and high voltage withstand devices usually have a large on-resistance, which leads to higher conduction loss. A three-winding switch-coupled inductor voltage doubler DC boost converter is provided.

[0004] A three-winding switch-coupled inductor voltage-doubling DC boost converter, comprising: diodes D1-D5, an inductor L1, an inductor L2, a capacitor C1, a power switch tube S, a three-winding coupled inductor and an output unit;

[0005] The positive electrode of the diode D1, one end of the inductor L1 and the diode D5 are used to be connected to the positive electrode of the power supply, the negative electrode of the diode D1 is respectively connected to one end of the inductor L2 and the negative electrode of the diode D2, the other end of the inductor L1 is respectively connected to the positive electrode of the diode D2 and the positive electrode of the diode D3, the other end of the inductor L2 is respectively connected to the positive electrode of the diode D4, the negative electrode of the diode D3 and one end of the capacitor C1, the negative electrode of the diode D4 is respectively connected to the drain of the power switch tube S and the winding in the three-winding coupled inductor The opposite-name end of winding N1 is connected to the opposite-name end of winding N3 in the three-winding coupled inductor, the other end of capacitor C1 is connected to the same-name end of winding N3 in the three-winding coupled inductor, the opposite-name end of winding N3 in the three-winding coupled inductor is respectively connected to the same-name ends of winding N1 and winding N2 in the three-winding coupled inductor, the cathode of diode D5 is connected to the opposite-name end of winding N2 in the three-winding coupled inductor, the source of power switch tube S is used to connect to the power supply ground, the output unit is connected in parallel between the source and drain of the power switch tube S, and the output unit serves as a load connection end.

[0006] Furthermore, the output unit includes an output diode D o and output capacitor C oThe drain of the power switch tube S is connected to the output diode D o The positive pole of the output diode D o The negative terminal of the output capacitor C o One end of the output capacitor C o The other end is connected to the source of the power switch tube S, and the output capacitor C o The two ends of the load are used as the connection ends.

[0007] Furthermore, the voltage output gain G of the three-winding switch-coupled inductor voltage-doubling DC boost converter is expressed as:

[0008]

[0009] Wherein, D is the conduction duty cycle of the power switch tube S, n1 is the turns ratio of winding N3 to N1 in the three-winding coupled inductor, and n2 is the turns ratio of winding N2 to N1 in the three-winding coupled inductor.

[0010] Furthermore, the operating range of the conduction duty cycle D of the power switch tube S is (0, 1).

[0011] Furthermore, the above three-winding switch-coupled inductor voltage-doubling DC boost converter includes two working modes, namely, the power switch tube S is turned on and the power switch tube S is turned off.

[0012] Furthermore, when the power switch tube S is turned on, the power supply is directly connected to the inductor L1, the diode D2 is reverse biased and cut off, the diode D1, the diode D3 and the diode D4 are all turned on, and the power supply charges the inductor L1 and the inductor L2; the power supply V in The winding N1 in the three-winding coupled inductor is charged through the diode D5 and the winding N2 in the three-winding coupled inductor, and the capacitor C1 charges the windings N1 and N3 in the three-winding coupled inductor; the output diode D o Reverse bias cutoff, output capacitor C o Provide independent power supply for loads.

[0013] Furthermore, when the power switch tube S is turned off, the diodes D1, D3 and D4 are all reverse biased and cut off, and the diode D2 is forward biased and turned on; the power supply charges the capacitor C1 through the inductor L1 and the inductor L2; the power supply charges the capacitor C1 through the inductor L1 and the inductor L2, the windings N1 and N3 in the three-winding coupled inductor, and the output diode D o For the load and output capacitor C o powered by.

[0014] The beneficial effects of the three-winding switch-coupled inductor voltage-doubling DC boost converter described in the present invention are:

[0015] DC voltage source V inDirectly connect the inductor L1. Since the inductor current is continuous, it can continuously provide relatively stable energy to the circuit, making the output capacitor C o The waveform changes of voltage, DC link voltage, etc. are relatively stable. Avoid instability of inductor voltage due to current discontinuity, which in turn causes instability such as a drop in DC link voltage, thereby causing distortion of the output waveform. A power switch S is used in the converter of the present invention, so that the converter has multiple working modes. The working modes are divided into an on state and an off state, which further optimizes the voltage distribution. This working mode allows the components to withstand appropriate voltages at different stages, avoiding certain components from being subjected to excessively high voltages, thereby reducing component voltage stress and further improving energy conversion efficiency and boosting capabilities. At the same time, the on-duty cycle range of the power switch S is adjustable, which increases the diversity of the control strategy, and can be applied to different application scenarios by changing different on-duty cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-winding switch-coupled inductor voltage-doubler DC boost converter;

[0017] Figure 2 The equivalent circuit diagram of a three-winding switch-coupled inductor voltage-doubler DC boost converter is shown in FIG. 1 , wherein (a) indicates that the switch is turned on, and (b) indicates that the switch is turned off;

[0018] Figure 3 : The experimental waveform diagram, where (a) represents the output capacitor voltage and the input voltage; (b) represents the switching diode voltage and the output diode voltage, (c) represents the diode D1 and D5 voltages, and (d) represents the capacitor voltage and the three-winding coupled inductor N2 current. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0020] Reference Figure 1 Specifically describe this embodiment, a three-winding switch-coupled inductor voltage-doubling DC boost converter described in this embodiment includes: diodes D1-D5, inductor L1, inductor L2, capacitor C1, output diode D o , output capacitor C o , power switch tube S and windings N1 to N3 of three-winding coupled inductor;

[0021] DC voltage source V in The positive electrode is respectively connected to the positive electrode of the diode D1, one end of the inductor L1 and the positive electrode of the diode D5;

[0022] The cathode of the diode D1 is connected to one end of the inductor L2 and the cathode of the diode D2 respectively;

[0023] The other end of the inductor L1 is connected to the anode of the diode D2 and the anode of the diode D3 respectively;

[0024] The other end of the inductor L2 is connected to the anode of the diode D4, the cathode of the diode D3 and one end of the capacitor C1 respectively;

[0025] The cathode of diode D4 is connected to the drain of power switch tube S, the opposite end of three-winding coupled inductor N1 and output diode D o The positive pole is connected;

[0026] The other end of capacitor C1 is connected to the same end of the three-winding coupled inductor N3;

[0027] The opposite-name ends of the three-winding coupled inductor N3 are respectively connected to the same-name ends of the winding N1 and the winding N2 in the three-winding coupled inductor;

[0028] The cathode of the diode D5 is connected to the opposite end of the three-winding coupled inductor N2;

[0029] Output diode D o The negative electrode of the output capacitor C o One end of is connected to one end of the load resistor R;

[0030] DC voltage source V in The negative electrode is connected to the source of the power switch tube S and the output capacitor C o The other end of is connected to the other end of the load resistor R.

[0031] The working principle and working process of a three-winding switch-coupled inductor voltage-doubling DC boost converter described in this embodiment are as follows:

[0032] like Figure 2 As shown, its working process is divided into two switching modes: switch on and switch off, which are described in detail as follows:

[0033] When the switch is turned on, the equivalent circuit is as follows Figure 2 As shown in (a), at this stage, the power switch tube S is turned on and the DC voltage source V in Directly connect the inductor L1, the diode D2 is reverse biased and cut off, the diodes D1, D3 and D4 are all turned on, and the DC voltage source V in Charge the inductors L1 and L2; DC voltage source V inThe three-winding coupled inductor N1 is charged through D5 and the three-winding coupled inductor N2, and the capacitor C1 charges the three-winding coupled inductor N1 and N3; the output diode D o Reverse bias cutoff, output capacitor C o The load resistor R is powered independently and this mode ends.

[0034] When the switch is off, the equivalent circuit is as follows Figure 2 As shown in (b), the power switch tube S remains off, diodes D1, D3 and D4 are reverse biased and cut off, and D2 is forward biased and turned on; the DC voltage source V in Capacitor C1 is charged through L1 and L2; DC voltage source V in Through L1 and L2, three-winding coupled inductors N1 and N3 and output diode D o is the load resistance R and the output capacitance C o Power is supplied and this mode ends.

[0035] According to the above analysis, the expression of the voltage output gain G of the three-winding switch-coupled inductor voltage-doubler DC boost converter is:

[0036]

[0037] Among them, D is the on-duty cycle of the power switch tube S, and its operating range is (0,1); n1 is the turns ratio of the three-winding coupled inductor N3 to N1, and n2 is the turns ratio of the three-winding coupled inductor N2 to N1.

[0038] The following is a description of the beneficial effects of this embodiment through specific experimental data:

[0039] like Figure 3 As shown, the input voltage is 50V, the output voltage is about 440V, n1=1, n2=0.5, D=0.4, and the load resistance R=200Ω. Figure 3 (a) is the output capacitor voltage of about 440V and the input voltage of 50V. Figure 3 (b) is the switching diode voltage and the output diode voltage. Figure 3 (c) is the voltage across diodes D1 and D5. Figure 3 (d) is the capacitor voltage and the current of the three-winding coupled inductor N2. As can be seen from the figure, the three-winding switch coupled inductor voltage doubler DC boost converter has a very high voltage output gain.

[0040] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A three-winding switch-coupled inductor voltage-doubling DC boost converter, characterized in that: include: Diodes D1 to D5, inductor L1, inductor L2, capacitor C1, power switch tube S, three-winding coupled inductor and output unit; The positive electrode of the diode D1, one end of the inductor L1 and the diode D5 are used to be connected to the positive electrode of the power supply, the negative electrode of the diode D1 is respectively connected to one end of the inductor L2 and the negative electrode of the diode D2, the other end of the inductor L1 is respectively connected to the positive electrode of the diode D2 and the positive electrode of the diode D3, the other end of the inductor L2 is respectively connected to the positive electrode of the diode D4, the negative electrode of the diode D3 and one end of the capacitor C1, the negative electrode of the diode D4 is respectively connected to the drain of the power switch tube S and the winding in the three-winding coupled inductor The opposite-name end of winding N1 is connected to the opposite-name end of winding N3 in the three-winding coupled inductor, the other end of capacitor C1 is connected to the same-name end of winding N3 in the three-winding coupled inductor, the opposite-name end of winding N3 in the three-winding coupled inductor is respectively connected to the same-name ends of winding N1 and winding N2 in the three-winding coupled inductor, the cathode of diode D5 is connected to the opposite-name end of winding N2 in the three-winding coupled inductor, the source of power switch tube S is used to connect to the power supply ground, the output unit is connected in parallel between the source and drain of the power switch tube S, and the output unit serves as a load connection end.

2. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 1, characterized in that: The output unit includes an output diode D o and output capacitor C o The drain of the power switch tube S is connected to the output diode D o The positive pole of the output diode D o The negative terminal of the output capacitor C o One end of the output capacitor C o The other end is connected to the source of the power switch tube S, and the output capacitor C o The two ends of the load are used as the connection ends.

3. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 1 or 2, characterized in that: The voltage output gain G of the three-winding switch-coupled inductor voltage-doubler DC boost converter is expressed as: Wherein, D is the conduction duty cycle of the power switch tube S, n1 is the turns ratio of winding N3 to N1 in the three-winding coupled inductor, and n2 is the turns ratio of winding N2 to N1 in the three-winding coupled inductor.

4. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 3, characterized in that: The operating range of the on-duty cycle D of the power switch tube S is (0,1).

5. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 1 or 2, characterized in that: The three-winding switch-coupled inductor voltage-doubling DC boost converter includes two working modes, namely, the power switch tube S is turned on and the power switch tube S is turned off.

6. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 5, characterized in that: When the power switch tube S is turned on, the power supply is directly connected to the inductor L1, the diode D2 is reverse biased and cut off, the diode D1, the diode D3 and the diode D4 are all turned on, and the power supply charges the inductor L1 and the inductor L2; the power supply V in The winding N1 in the three-winding coupled inductor is charged through the diode D5 and the winding N2 in the three-winding coupled inductor, and the capacitor C1 charges the windings N1 and N3 in the three-winding coupled inductor; the output diode D o Reverse bias cutoff, output capacitor C o Provide independent power supply for loads.

7. A three-winding switch-coupled inductor voltage-doubler DC boost converter according to claim 5, characterized in that: When the power switch tube S is turned off, diodes D1, D3 and D4 are all reverse biased and cut off, and diode D2 is forward biased and turned on; the power supply charges capacitor C1 through inductors L1 and L2; the power supply charges capacitor C1 through inductors L1 and L2, windings N1 and N3 in the three-winding coupled inductor, and output diode D o For the load and output capacitor C o powered by.

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